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DIY Brake servo (booster) re-build with new o-rings and a new shaft seal

For the following cars 533,535,m535,m5,633,635,m635,m6,735.

This Do It Yourself (DIY) is to re-build the Brake Servo Booster #34331156925
It includes a step by step procedure to repair the internal rubber seal and 5 o-rings.
I just up dated this post DIY, I have added a new shaft seal and a how to replace the seal.

I also added a new helpfull hint for the re-build.
Where the grub screw, screws into the booster cylinder there can be a burr created by the grub screw, on the interior. This burr can cut the 38mm O-ring, and also damage the 2 white high pressure teflon piston rings.
Thanks to (tn).

New-Upgraded DIY rebuild kit for the Brake Servo Booster

Hi Forum Members,

I now have all of the interior components for the complete re-build of the Brake Servo (booster). I have received the new teflon interior high pressure piston o-rings. I installed these new parts into my M6 over the weekend. The road test was a success, all of the parts work as they should!

The new up-graded kit includes the 5 internal rubber o-rings, the 2 teflon piston o-rings, and a new shaft seal.

I have also up-graded the Picasa Link, I took more photos and added more captions to show the correct method that I used in the assembly of the booster.

The new price is $24.95 + shipping $1.95 USA, TOTAL $26.90 USD.

International is also $24.95 + shipping $3.95 International TOTAL $28.90 USD.

Here this the link to the DIY, step by step instruction, of the booster repair.

I am also offering a QUICK FIX kit, this includes just the 38mm o-ring, and the shaft seal only. Price is $7.95 + $1.95 shipping USA TOTAL $9.90 USD.
International is also $7.95 + $3.95 shipping International TOTAL $11.90 USD.

Hydraulic brake servo booster 10 piece repair kit and Repair Service

For the following BMW cars
e28,533,535,m535,m5, part # 34331156925
e24,633,635,m635,m6,L6, part # 34331156925
e32,735 only. part # 34331156925

e23,733,735,745 part # 34331152825

This Do It Yourself (DIY) is to re-build the Brake Servo Booster, all of the 10 piece interior repair kit are identical, for both part numbers

I recently rebuilt another hydraulic brake servo booster, and I was amazed at how the rubber o-rings were deformed and hardened. They are now an oblong shape. The large o-ring 38.0mm x 3.0mm, at the front of the booster. It now measures 2.55mm high instead of 3mm. And is 3.28mm thick, were it should be again be 3.0mm. And it is noticeably more brittle. The smallest o-ring was brittle and it broke when removed.

I am now offering to rebuild your booster for you, using my 10 piece repair kit.
I am charging $85.00 + shipping back to you. Cont USA only. USD
If you send me your address, and I can give you an accurate shipping quote, via FedEx Ground home delivery.
Just send your booster to me, with a $ check. PayPal add 4%

I also have a couple of spare rebuilt booster, that I can send to you. And you return your old core to me, shipping on you.
Same price of $85.00 + ship + $60.00 core. USD
PayPal add 4% [email protected]

Special note! Please read! Some BAD boosters are being sold.

I had a client of mine who sent me a leaking booster. When I opened it up to repair, I noticed that it had an incorrect shaft seal installed.

On top of that, the shaft seal was installed up-side down, and missing the garter spring.

My client told me that his first Cardone from Parts Geek leaked as soon as it was installed, he sent it back to Parts Geek and they sent him another.

When he installed the second one, it also leaked.
And thats when he called me, and I used my rebuild service and sent him one of my rebuilt spares.

When I received his core back, I set to rebuild it for the next client.
I was shocked, the shaft seal was upside down, I then pressed the shaft seal out of the black plastic cup. The shaft seal specs are 9.5mm i.d. x 22.0mm o.d. and thickness of 6mm.
The A-1 Cardone is 10.0mm i.d., way too big. It is made in China by YEI Shien, part #A19168 10x22x6.
Because it was in backwards the garter spring came off, or was never there in the first place.
I am going to also attach some photos, of the suspect seal front and back, and what a garter spring looks like.